Abstract: To enhance the effect iveness of routine breeding,it is important to evaluate simply,quickly,repeatedly,non-devastatingly and less expensively the characteristics related to yield.Field studies were conducted in 1998 and 1999 to investigate solar radiation distribution in the canopies of four leading variet ies: Jinmai 2,Jing 411,Zhongmai 9 and 8017-2,with a digital plant canopy imager.The results showed that the middle of filling stage was a suitable period to evaluate solar radiation distribution in wheat canopy.In the different canopies with similar plant density,ranges 615-710 million spikes perha,the yearly radiations of transmission coefficients for radiation penetration(TCRP)and TCDP were not significant.However,the differences between varieties are significant.A negative correlation is found between the extinction coefficient(K)in upper part of canopy and that in the lower part,and that in canopy average.It is suggested that the genotype with less K value in upper part of canopy should be selected in wheat breeding.

Key words: Wheat, Canopy, Extinction coefficient

CLC Number: 

• S512.110